Private companies — especially those in tech — are raising billions of dollars to delay, and sometimes even shun, a path to public markets. These efforts are creating vast wealth for employees and early-stage stakeholders, while shutting out most people who can’t invest in them through things such as 401(k) retirement accounts provided by some US companies. The numbers show a dramatic shift from just a few decades ago, and the trend has become even more stark as initial public offerings (IPOs) h